1. Field of the Invention
The invention relates to a method and apparatus for facilitating the measurement of agricultural spray deposits and spray retention on plant leaves.
2. Description of the Prior Art
Application of agricultural chemicals by aerial and ground spraying has long been prevalent in the U.S. and worldwide. However, lack of accurate information regarding the retention of sprays on plant surfaces and existing residue levels, could lead to excessive or insufficient field application or sub-optimal application protocols, ultimately resulting in increased expenses to the user or possible contamination of the environment.
Although artificial spray sampling collectors may be used, such devices typically suffer from the inherent disadvantage of disturbing the sampling environment to such an extent that extrapolating data to predict spray deposition on target plants is uncertain. Ware et al. (1975, J. Economic Entomology, 68:549-550) proposed avoiding this uncertainty by sampling actual target surfaces to determine the gross deposit quantity. Briefly, field sprayed cotton stalks were cut and immersed in their entirety in a large solvent bath. Samples from the bath were later analyzed for DDT content. More recently, Carlton and Bouse (1988, Trans. ASAE, 31:990-997) disclosed a cylindrical collector for sampling aerial sprays. In spite of these developments there remains a persistent need for simple methods or devices to facilitate the measurement of agricultural spray deposits and spray retention on plant leaves.